Within the scope of minimally invasive intervention actions, in which for example catheters are inserted into hollow spaces, the coronary blood vessels for example, the optical presentation of the moving instrument plays a central role in relation to the examination region in enabling the physician to navigate the instrument which is no longer visible to him after introducing it into the patient. To this end, a method is known whereby an X-ray fluoroscopy device is used to continuously record and output two-dimensional X-ray images which the physician uses for navigation purposes. The navigation using these 2D images is difficult on account of the lack of depth information or spatial information, and in addition the stress on the patient as a result of the continuous radiation image recording during the intervention is relatively high.